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Our future, our universe, and other weighty topics

Saturday, June 28, 2014

Galaxy Spin Bias: A Page From the Cosmic “Book of the Damned”

Charles
Fort was a writer who wrote four books describing strange
inexplicable phenomena. One of these books was called The Book of
the Damned. For example, he discussed alleged cases of
teleportation, poltergeist activity, mysterious disappearances,
inexplicable spontaneous fires, UFOs, ball lightning, and cases of
fish, frogs, and organic material mysteriously falling from the
sky. The title refers to phenomena that have been “damned” in
the sense of being excluded from consideration by modern scientists,
because the phenomena fall outside of their theories. Fort's works
were so successful that nowadays the term “Fortean” is used for
such hard-to-explain phenomena. An entertaining web site that
discusses such phenomena is http://www.unexplained-mysteries.com/.

We might say there is an
earthly “Book of the Damned,” and a cosmic “Book of the
Damned.” Inside the cosmic “Book of
the Damned” are items discovered by astronomers that are all but
impossible to explain within the framework of existing theories. One
strange example along these lines is the odd case of spiral galaxy
spins.

All spiral galaxies rotate. A
spiral galaxy can either rotate in a clockwise direction or a
counter-clockwise direction. The directions are called either
left-handed or right-handed, depending on the side to which the
bottom spiral arm is pointing. In the picture below, we see the
difference between the two types of spin.

Scientists originally
expected that 50% of the spiral galaxies would spin in a left-handed
direction, and 50% of the spiral galaxies would spin in a
right-handed direction. That is what we would expect to occur by
chance.

Physicist Michael Longo and
his helpers studied more than 15,000 galaxies to determine which
direction they were spinning (something that seems like the most
tedious assignment imaginable). The end result was very
surprising. Instead of finding that spiral galaxies always spin in
one direction 50% of the time and the other direction 50% of the
time, Longo found that in some parts of the sky galaxies prefer to
spin one way or the other significantly more frequently.

Longo's results are shown
below. The diagram shows different directions of the sky. The numbers along the outer circumference of the circle summarize the overall spin bias for a particular direction of the sky. The results are very strange. In some directions of the sky
there is an almost exact balance between galaxies that are spinning in a
“left-handed” way and galaxies spinning in the opposite,
“right-handed” way. But in other directions of the sky,
“left-handedness” can be preferred by as much as 7% over
“right-handedness.”

While
it may seem small, such a 7% preference is really huge, when one
considers the law of large numbers, which dictates that when you have
very many trials (such as more than 1000) the deviation from the
expected chance result should be very, very small. The law of large
numbers dictates, for example, that if you flip a coin 10,000 times,
there is only the tiniest chance that the number of “Heads” flips
will be more than 51%.

There
is no easy way to reconcile Longo's finding with the prevailing
assumptions of modern astronomers. So when Longo's results were
announced, scientists took the convenient route of thinking: we'll
just ignore this, because after all, it's only one study.

But
then the next year scientist Lior Shamir produced a scientific paper
presenting the results of a much larger analysis on spiral galaxy
spins. Shamir analyzed 126,501 galaxies, and found that the effect
reported by Longo is very real: spiral galaxies prefer to spin in a
left-handed direction in a particular direction of the sky. The
degree of preference is about the same reported by Longo, about 7%.

How
could such a thing be happening by chance? There has been talk that a
“rotation of the entire universe” might be an explanation, but
the suitability of such an explanation is very questionable, and the
idea of a rotating universe doesn't fit in with prevailing
astrophysical theories.

Faced
with a second scientific paper showing this mysterious anomaly that
spiral galaxies prefer to spin in one direction, did scientists start
giving this matter great attention? No. They pretty much continued to
ignore the anomaly, putting the finding in the cosmic “Book of the
Damned,” where the finding continues to attract almost no
attention.

Copyright Notice

All posts on this blog are authored by Mark Mahin, and are protected by copyright. Copyright 2013-2014 by Mark Mahin. All rights reserved. Any resemblance between any fictional character and any real person is purely coincidental.